It's classed as an "Adaptogen". Vague term, but it's new to the lexicon, so yet to really be quantified. Used first by Soviets in Space program. Shown to boost adrenal function as well as and offset negative effects on stress neurophysiology--ie make oxygen use more efficient. Seems to boost overall resilience, from what I've read, so good all around approach rather than targeted for specific symptoms. Not really enough research out there yet to narrow down the mechanisms of action and pick them apart to apply to specific symptoms. I'm sure as soon as they do they'll pharamacalize it.
But it seems that general approaches to overall resilience are better, in the long run. As with everything we seem to try to pick apart to turn it to specific willful application, when we begin targeting one symptom or another for one specific effect, we begin throwing off all the others which are being affected in ways we haven't figured out yet, and so aren't aware of. Just look at what we've done to the ecosystem, for example, by "sciencing" apart all of the particular uses of our environment and turning them to our specific uses, without regard to the feedback loops inolved in affecting the big picture in other areas. The tool makers curse. Blame our opposable thumbs, maybe. Who knows. But it's human nature, and see where that's gotten us. All too often the human is the microcosm of the environment, and we "over-select" at our own risk, in our hubris thinking we've gotten it all figured out enough to promote just one thing, without realizing it comes at the expense of so many others.
This would seem a good approach, especially since adrenal function and stress physiology underlies so much of anxiety symptoms. I've read more than a little about it and haven't run across any untoward effects or testimony at all, and it's been around for a long time, just not in the west (of course), even being used in an organized systematic ways in science based milieu such as the soviet space program, as I mentioned, and to good enough effect to become relied upon as a standard there.
One word of caution, you want a good brand, and one standardized to at least "3% Rosavins" (what have been proven to be the active constituent element--you can eat bark from the pecan tree, but that's not really what you're after, is it?)
Also, as I remember, there are two different kinds (and this is just off the top of my head and it's been several years, so do your own research)--a red, and a gold? I believe. There are different effects between the two--and I believe it's the gold which is more potent, more expensive and harder to find. Kind of like differences in Ginseng, for example.
So before going off willy-nilly and saying "this didn't work", etc., please at least do some basic research before you buy, please, and post the specifics of what you've used. If you don't, you haven't really told anyone anything, after all (if not specific brand).